[mythtv] Zoom -vs- Aspect -- need a custom setting

Daniel Kristjansson danielk at cuymedia.net
Mon May 7 13:37:30 UTC 2007

On Mon, 2007-05-07 at 09:18 -0400, David Frascone wrote:
> Daniel Kristjansson wrote:
> > Is the aspect ratio of the image correct?   
> I can only assume that the aspect is *not* correct.  The image fills the 
> screen horizontally, but not vertically.  Since the image *should* be 
> 16:9, then it should also fill vertically. 

But it could be stripping away a portion of the image so
that the aspect ratio is still correct. Does it actually
look squished?

> Sounds good -- but -- should I even start, since my aspect is still 
> screwy on the firewire video?

You shouldn't start until the aspect ratio is correct. MythTV
uses the aspect ratio of the pixels in the video + the pixel
aspect ratio of the video + the aspect ratio of the pixels on
the screen + the pixel aspect ratio of the screen to compute
how to show the video. It looks like the latter two are correct
now that HDHomeRun video looks correct and it is hard to get
the second one wrong, but if the STBs transcode sets the pixel
aspect ratio incorrectly then we should fix that problem first.
How pixel aspect ratios are set was changed between MPEG-1
and MPEG-2. If the STB uses an MPEG-1 encoder, or the developer
who wrote that portion of the STB software referenced the wrong
standard for the aspect ratio field, this would confuse MythTV.

-- Daniel

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